SCO 5.0.5 on compaq presariolaptop C773tu

i want to install sco unix 5.0.5 on compaq presario laptop c773tu dual boot with windos xp.
the HDD is 160 GB
RAM 2046 MB ddr2.
I have created partitions and loaded Win XP
While installing SCO Unix 5.0.5 i get the following problem
1)memory excessively fragmented. I get around it by sepcifying the following at the boot prompt mem=1m-16m,16-2048m at boot:
2) the interative fdisk/divvy doesnot run.
3)the size of hard disk is shown as 8 GB
please help me install sco unix on the laptop.
thanks in advance.